staking miner: reuse ws conn for remote-ext (#4849)

* staking miner: use config for emergency solution

Fixes #4678

* bump jsonrpsee

* run `monitor_cmd_for` until the connection is closed

* new tokio task for submit_and_watch xt

* re-use header subscription

* update jsonrpsee + simplify code

* revert polkadot runtime changes

* fix grumbles

* Update utils/staking-miner/src/monitor.rs

* staking miner: reuse ws conn for remote-ext

* Revert "revert polkadot runtime changes"

This reverts commit 5fddbbec40702c122b079526915cabac8facdbc1.

* cargo fmt

* revert unintentional change

* revert unintentional change

* add type SharedRpcClient

* cargo fmt

* fix nits

* spelling

* use tracing_subcriber and cleanup

* remove some needless clones

* fix some nits

* fix spellcheck

polkadot/Cargo.lock

@@ -4111,6 +4111,15 @@ dependencies = [
  "regex-automata",
 ]
 
+[[package]]
+name = "matchers"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8263075bb86c5a1b1427b5ae862e8889656f126e9f77c484496e8b47cf5c5558"
+dependencies = [
+ "regex-automata",
+]
+
 [[package]]
 name = "matches"
 version = "0.1.9"
@@ -9170,7 +9179,7 @@ dependencies = [
  "thiserror",
  "tracing",
  "tracing-log",
- "tracing-subscriber",
+ "tracing-subscriber 0.2.25",
 ]
 
 [[package]]
@@ -10264,7 +10273,7 @@ dependencies = [
  "sp-std",
  "tracing",
  "tracing-core",
- "tracing-subscriber",
+ "tracing-subscriber 0.2.25",
 ]
 
 [[package]]
@@ -10379,7 +10388,6 @@ name = "staking-miner"
 version = "0.9.17"
 dependencies = [
  "clap",
- "env_logger 0.9.0",
  "frame-election-provider-support",
  "frame-support",
  "frame-system",
@@ -10407,6 +10415,7 @@ dependencies = [
  "sub-tokens",
  "thiserror",
  "tokio",
+ "tracing-subscriber 0.3.8",
  "westend-runtime",
 ]
 
@@ -10782,9 +10791,9 @@ checksum = "3bf63baf9f5039dadc247375c29eb13706706cfde997d0330d05aa63a77d8820"
 
 [[package]]
 name = "thread_local"
-version = "1.1.3"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8018d24e04c95ac8790716a5987d0fec4f8b27249ffa0f7d33f1369bdfb88cbd"
+checksum = "5516c27b78311c50bf42c071425c560ac799b11c30b31f87e3081965fe5e0180"
 dependencies = [
  "once_cell",
 ]
@@ -11086,7 +11095,7 @@ dependencies = [
  "ansi_term",
  "chrono",
  "lazy_static",
- "matchers",
+ "matchers 0.0.1",
  "parking_lot 0.11.2",
  "regex",
  "serde",
@@ -11100,6 +11109,24 @@ dependencies = [
  "tracing-serde",
 ]
 
+[[package]]
+name = "tracing-subscriber"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "74786ce43333fcf51efe947aed9718fbe46d5c7328ec3f1029e818083966d9aa"
+dependencies = [
+ "ansi_term",
+ "lazy_static",
+ "matchers 0.1.0",
+ "regex",
+ "sharded-slab",
+ "smallvec",
+ "thread_local",
+ "tracing",
+ "tracing-core",
+ "tracing-log",
+]
+
 [[package]]
 name = "trie-db"
 version = "0.23.1"

polkadot/utils/staking-miner/Cargo.toml

@@ -7,8 +7,8 @@ edition = "2018"
 [dependencies]
 clap = { version = "3.0", features = ["derive", "env"] }
 codec = { package = "parity-scale-codec", version = "2.0.0" }
-env_logger = "0.9.0"
+tracing-subscriber = { version = "0.3.8", features = ["env-filter"]   }
-jsonrpsee = { version = "0.8", features = ["ws-client"] }
+jsonrpsee = { version = "0.8", features = ["ws-client", "macros"] }
 log = "0.4.11"
 paste = "1.0.6"
 serde = "1.0.136"

polkadot/utils/staking-miner/src/dry_run.rs

@@ -16,12 +16,10 @@
 
 //! The dry-run command.
 
-use crate::{
+use crate::{prelude::*, rpc::*, signer::Signer, DryRunConfig, Error, SharedRpcClient};
-	prelude::*, rpc_helpers::*, signer::Signer, DryRunConfig, Error, SharedConfig, WsClient,
-};
 use codec::Encode;
 use frame_support::traits::Currency;
-use jsonrpsee::rpc_params;
+use sp_core::Bytes;
 use sp_npos_elections::ElectionScore;
 
 /// Forcefully create the snapshot. This can be used to compute the election at anytime.
@@ -39,10 +37,10 @@ fn force_create_snapshot<T: EPM::Config>(ext: &mut Ext) -> Result<(), Error<T>>
 
 /// Helper method to print the encoded size of the snapshot.
 async fn print_info<T: EPM::Config>(
-	client: &WsClient,
+	rpc: &SharedRpcClient,
 	ext: &mut Ext,
 	raw_solution: &EPM::RawSolution<EPM::SolutionOf<T>>,
-	extrinsic: sp_core::Bytes,
+	extrinsic: &Bytes,
 ) where
 	<T as EPM::Config>::Currency: Currency<T::AccountId, Balance = Balance>,
 {
@@ -79,12 +77,8 @@ async fn print_info<T: EPM::Config>(
 		);
 	});
 
-	let info = rpc::<pallet_transaction_payment::RuntimeDispatchInfo<Balance>>(
+	let info = rpc.payment_query_info(&extrinsic, None).await;
-		client,
+
-		"payment_queryInfo",
-		rpc_params! { extrinsic },
-	)
-	.await;
 	log::info!(
 		target: LOG_TARGET,
 		"payment_queryInfo: (fee = {}) {:?}",
@@ -116,14 +110,13 @@ fn find_threshold<T: EPM::Config>(ext: &mut Ext, count: usize) {
 macro_rules! dry_run_cmd_for { ($runtime:ident) => { paste::paste! {
 	/// Execute the dry-run command.
 	pub(crate) async fn [<dry_run_cmd_ $runtime>](
-		client: &WsClient,
+		rpc: SharedRpcClient,
-		shared: SharedConfig,
 		config: DryRunConfig,
 		signer: Signer,
 	) -> Result<(), Error<$crate::[<$runtime _runtime_exports>]::Runtime>> {
 		use $crate::[<$runtime _runtime_exports>]::*;
 		let mut ext = crate::create_election_ext::<Runtime, Block>(
-			shared.uri.clone(),
+			rpc.clone(),
 			config.at,
 			vec!["Staking".to_string(), "System".to_string()],
 		).await?;
@@ -131,7 +124,7 @@ macro_rules! dry_run_cmd_for { ($runtime:ident) => { paste::paste! {
 
 		let (raw_solution, witness) = crate::mine_with::<Runtime>(&config.solver, &mut ext, false)?;
 
-		let nonce = crate::get_account_info::<Runtime>(client, &signer.account, config.at)
+		let nonce = crate::get_account_info::<Runtime>(&rpc, &signer.account, config.at)
 			.await?
 			.map(|i| i.nonce)
 			.expect("signer account is checked to exist upon startup; it can only die if it \
@@ -143,7 +136,7 @@ macro_rules! dry_run_cmd_for { ($runtime:ident) => { paste::paste! {
 		let extrinsic = ext.execute_with(|| create_uxt(raw_solution.clone(), witness, signer.clone(), nonce, tip, era));
 
 		let bytes = sp_core::Bytes(extrinsic.encode().to_vec());
-		print_info::<Runtime>(client, &mut ext, &raw_solution, bytes.clone()).await;
+		print_info::<Runtime>(&rpc, &mut ext, &raw_solution, &bytes).await;
 
 		let feasibility_result = ext.execute_with(|| {
 			EPM::Pallet::<Runtime>::feasibility_check(raw_solution.clone(), EPM::ElectionCompute::Signed)
@@ -157,9 +150,8 @@ macro_rules! dry_run_cmd_for { ($runtime:ident) => { paste::paste! {
 		});
 		log::info!(target: LOG_TARGET, "dispatch result is {:?}", dispatch_result);
 
-		let outcome = rpc_decode::<sp_runtime::ApplyExtrinsicResult>(client, "system_dryRun", rpc_params!{ bytes })
+		let dry_run_fut = rpc.dry_run(&bytes, None);
-			.await
+		let outcome: sp_runtime::ApplyExtrinsicResult = await_request_and_decode(dry_run_fut).await.map_err::<Error<Runtime>, _>(Into::into)?;
-			.map_err::<Error<Runtime>, _>(Into::into)?;
 		log::info!(target: LOG_TARGET, "dry-run outcome is {:?}", outcome);
 		Ok(())
 	}

polkadot/utils/staking-miner/src/emergency_solution.rs

@@ -16,19 +16,19 @@
 
 //! The emergency-solution command.
 
-use crate::{prelude::*, EmergencySolutionConfig, Error, SharedConfig};
+use crate::{prelude::*, EmergencySolutionConfig, Error, SharedRpcClient};
 use codec::Encode;
 use std::io::Write;
 
 macro_rules! emergency_solution_cmd_for { ($runtime:ident) => { paste::paste! {
 	/// Execute the emergency-solution command.
 	pub(crate) async fn [<emergency_solution_cmd_ $runtime>](
-		shared: SharedConfig,
+		client: SharedRpcClient,
 		config: EmergencySolutionConfig,
 	) -> Result<(), Error<$crate::[<$runtime _runtime_exports>]::Runtime>> {
 		use $crate::[<$runtime _runtime_exports>]::*;
 
-		let mut ext = crate::create_election_ext::<Runtime, Block>(shared.uri.clone(), config.at, vec![]).await?;
+		let mut ext = crate::create_election_ext::<Runtime, Block>(client, config.at, vec![]).await?;
 		let (raw_solution, _witness) = crate::mine_with::<Runtime>(&config.solver, &mut ext, false)?;
 
 		ext.execute_with(|| {

polkadot/utils/staking-miner/src/main.rs

@@ -32,7 +32,7 @@ mod dry_run;
 mod emergency_solution;
 mod monitor;
 mod prelude;
-mod rpc_helpers;
+mod rpc;
 mod signer;
 
 pub(crate) use prelude::*;
@@ -43,8 +43,12 @@ use frame_election_provider_support::NposSolver;
 use frame_support::traits::Get;
 use jsonrpsee::ws_client::{WsClient, WsClientBuilder};
 use remote_externalities::{Builder, Mode, OnlineConfig};
+use rpc::{RpcApiClient, SharedRpcClient};
 use sp_npos_elections::ExtendedBalance;
 use sp_runtime::{traits::Block as BlockT, DeserializeOwned};
+use tracing_subscriber::{fmt, EnvFilter};
+
+use std::{ops::Deref, sync::Arc};
 
 pub(crate) enum AnyRuntime {
 	Polkadot,
@@ -90,10 +94,10 @@ macro_rules! construct_runtime_prelude {
 					let extra: SignedExtra = crate::[<signed_ext_builder_ $runtime>](nonce, tip, era);
 					let raw_payload = SignedPayload::new(call, extra).expect("creating signed payload infallible; qed.");
 					let signature = raw_payload.using_encoded(|payload| {
-						pair.clone().sign(payload)
+						pair.sign(payload)
 					});
 					let (call, extra, _) = raw_payload.deconstruct();
-					let address = <Runtime as frame_system::Config>::Lookup::unlookup(account.clone());
+					let address = <Runtime as frame_system::Config>::Lookup::unlookup(account);
 					let extrinsic = UncheckedExtrinsic::new_signed(call, address, signature.into(), extra);
 					log::debug!(
 						target: crate::LOG_TARGET, "constructed extrinsic {} with length {}",
@@ -229,7 +233,7 @@ macro_rules! any_runtime_unit {
 enum Error<T: EPM::Config> {
 	Io(#[from] std::io::Error),
 	JsonRpsee(#[from] jsonrpsee::core::Error),
-	RpcHelperError(#[from] rpc_helpers::RpcHelperError),
+	RpcHelperError(#[from] rpc::RpcHelperError),
 	Codec(#[from] codec::Error),
 	Crypto(sp_core::crypto::SecretStringError),
 	RemoteExternalities(&'static str),
@@ -368,7 +372,7 @@ struct Opt {
 /// Build the Ext at hash with all the data of `ElectionProviderMultiPhase` and any additional
 /// pallets.
 async fn create_election_ext<T: EPM::Config, B: BlockT + DeserializeOwned>(
-	uri: String,
+	client: SharedRpcClient,
 	at: Option<B::Hash>,
 	additional: Vec<String>,
 ) -> Result<Ext, Error<T>> {
@@ -381,7 +385,7 @@ async fn create_election_ext<T: EPM::Config, B: BlockT + DeserializeOwned>(
 	pallets.extend(additional);
 	Builder::<B>::new()
 		.mode(Mode::Online(OnlineConfig {
-			transport: uri.into(),
+			transport: client.into_inner().into(),
 			at,
 			pallets,
 			..Default::default()
@@ -493,13 +497,13 @@ fn mine_dpos<T: EPM::Config>(ext: &mut Ext) -> Result<(), Error<T>> {
 }
 
 pub(crate) async fn check_versions<T: frame_system::Config + EPM::Config>(
-	client: &WsClient,
+	rpc: &SharedRpcClient,
 ) -> Result<(), Error<T>> {
 	let linked_version = T::Version::get();
-	let on_chain_version =
+	let on_chain_version = rpc
-		rpc_helpers::rpc::<sp_version::RuntimeVersion>(client, "state_getRuntimeVersion", None)
+		.runtime_version(None)
-			.await
+		.await
-			.expect("runtime version RPC should always work; qed");
+		.expect("runtime version RPC should always work; qed");
 
 	log::debug!(target: LOG_TARGET, "linked version {:?}", linked_version);
 	log::debug!(target: LOG_TARGET, "on-chain version {:?}", on_chain_version);
@@ -517,20 +521,13 @@ pub(crate) async fn check_versions<T: frame_system::Config + EPM::Config>(
 
 #[tokio::main]
 async fn main() {
-	env_logger::Builder::from_default_env()
+	fmt().with_env_filter(EnvFilter::from_default_env()).init();
-		.format_module_path(true)
+
-		.format_level(true)
-		.init();
 	let Opt { shared, command } = Opt::parse();
 	log::debug!(target: LOG_TARGET, "attempting to connect to {:?}", shared.uri);
 
-	let client = loop {
+	let rpc = loop {
-		let maybe_client = WsClientBuilder::default()
+		match SharedRpcClient::new(&shared.uri).await {
-			.connection_timeout(std::time::Duration::new(20, 0))
-			.max_request_body_size(u32::MAX)
-			.build(&shared.uri)
-			.await;
-		match maybe_client {
 			Ok(client) => break client,
 			Err(why) => {
 				log::warn!(
@@ -538,14 +535,12 @@ async fn main() {
 					"failed to connect to client due to {:?}, retrying soon..",
 					why
 				);
-				std::thread::sleep(std::time::Duration::from_millis(2500));
+				tokio::time::sleep(std::time::Duration::from_millis(2500)).await;
 			},
 		}
 	};
 
-	let chain = rpc_helpers::rpc::<String>(&client, "system_chain", None)
+	let chain: String = rpc.system_chain().await.expect("system_chain infallible; qed.");
-		.await
-		.expect("system_chain infallible; qed.");
 	match chain.to_lowercase().as_str() {
 		"polkadot" | "development" => {
 			sp_core::crypto::set_default_ss58_version(
@@ -591,26 +586,26 @@ async fn main() {
 	log::info!(target: LOG_TARGET, "connected to chain {:?}", chain);
 
 	any_runtime_unit! {
-		check_versions::<Runtime>(&client).await
+		check_versions::<Runtime>(&rpc).await
 	};
 
 	let signer_account = any_runtime! {
-		signer::signer_uri_from_string::<Runtime>(&shared.seed, &client)
+		signer::signer_uri_from_string::<Runtime>(&shared.seed, &rpc)
 			.await
 			.expect("Provided account is invalid, terminating.")
 	};
 
 	let outcome = any_runtime! {
-		match command.clone() {
+		match command {
-			Command::Monitor(c) => monitor_cmd(client, shared, c, signer_account).await
+			Command::Monitor(cmd) => monitor_cmd(rpc, cmd, signer_account).await
 				.map_err(|e| {
 					log::error!(target: LOG_TARGET, "Monitor error: {:?}", e);
 				}),
-			Command::DryRun(c) => dry_run_cmd(&client, shared, c, signer_account).await
+			Command::DryRun(cmd) => dry_run_cmd(rpc, cmd, signer_account).await
 				.map_err(|e| {
 					log::error!(target: LOG_TARGET, "DryRun error: {:?}", e);
 				}),
-			Command::EmergencySolution(c) => emergency_solution_cmd(shared.clone(), c).await
+			Command::EmergencySolution(cmd) => emergency_solution_cmd(rpc, cmd).await
 				.map_err(|e| {
 					log::error!(target: LOG_TARGET, "EmergencySolution error: {:?}", e);
 				}),

polkadot/utils/staking-miner/src/monitor.rs

@@ -16,28 +16,21 @@
 
 //! The monitor command.
 
-use crate::{prelude::*, rpc_helpers::*, signer::Signer, Error, MonitorConfig, SharedConfig};
+use crate::{prelude::*, rpc::*, signer::Signer, Error, MonitorConfig, SharedRpcClient};
 use codec::Encode;
-use jsonrpsee::{
+use jsonrpsee::core::Error as RpcError;
-	core::{
-		client::{Subscription, SubscriptionClientT},
-		Error as RpcError,
-	},
-	rpc_params,
-	ws_client::WsClient,
-};
 use sc_transaction_pool_api::TransactionStatus;
 use sp_core::storage::StorageKey;
-use std::sync::Arc;
 use tokio::sync::mpsc;
 
 /// Ensure that now is the signed phase.
-async fn ensure_signed_phase<T: EPM::Config, B: BlockT>(
+async fn ensure_signed_phase<T: EPM::Config, B: BlockT<Hash = Hash>>(
-	client: &WsClient,
+	rpc: &SharedRpcClient,
 	at: B::Hash,
 ) -> Result<(), Error<T>> {
 	let key = StorageKey(EPM::CurrentPhase::<T>::hashed_key().to_vec());
-	let phase = get_storage::<EPM::Phase<BlockNumber>>(client, rpc_params! {key, at})
+	let phase = rpc
+		.get_storage_and_decode::<EPM::Phase<BlockNumber>>(&key, Some(at))
 		.await
 		.map_err::<Error<T>, _>(Into::into)?
 		.unwrap_or_default();
@@ -71,23 +64,21 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 
 	/// The monitor command.
 	pub(crate) async fn [<monitor_cmd_ $runtime>](
-		client: WsClient,
+		rpc: SharedRpcClient,
-		shared: SharedConfig,
 		config: MonitorConfig,
 		signer: Signer,
 	) -> Result<(), Error<$crate::[<$runtime _runtime_exports>]::Runtime>> {
 		use $crate::[<$runtime _runtime_exports>]::*;
 		type StakingMinerError = Error<$crate::[<$runtime _runtime_exports>]::Runtime>;
 
-		let (sub, unsub) = if config.listen == "head" {
+		let heads_subscription = ||
-			("chain_subscribeNewHeads", "chain_unsubscribeNewHeads")
+			if config.listen == "head" {
-		} else {
+				rpc.subscribe_new_heads()
-			("chain_subscribeFinalizedHeads", "chain_unsubscribeFinalizedHeads")
+			} else {
-		};
+				rpc.subscribe_finalized_heads()
+			};
 
-		let mut subscription: Subscription<Header> = client.subscribe(&sub, None, &unsub).await?;
+		let mut subscription = heads_subscription().await?;
-
-		let client = Arc::new(client);
 		let (tx, mut rx) = mpsc::unbounded_channel::<StakingMinerError>();
 
 		loop {
@@ -97,8 +88,8 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 						Some(Ok(r)) => r,
 						// Custom `jsonrpsee` message sent by the server if the subscription was closed on the server side.
 						Some(Err(RpcError::SubscriptionClosed(reason))) => {
-							log::warn!(target: LOG_TARGET, "subscription to {} terminated: {:?}. Retrying..", sub, reason);
+							log::warn!(target: LOG_TARGET, "subscription to `subscribeNewHeads/subscribeFinalizedHeads` terminated: {:?}. Retrying..", reason);
-							subscription = client.subscribe(&sub, None, &unsub).await?;
+							subscription = heads_subscription().await?;
 							continue;
 						}
 						Some(Err(e)) => {
@@ -109,8 +100,8 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 						//	- the connection was closed.
 						//	- the subscription could not keep up with the server.
 						None => {
-							log::warn!(target: LOG_TARGET, "subscription to {} terminated. Retrying..", sub);
+							log::warn!(target: LOG_TARGET, "subscription to `subscribeNewHeads/subscribeFinalizedHeads` terminated. Retrying..");
-							subscription = client.subscribe(&sub, None, &unsub).await?;
+							subscription = heads_subscription().await?;
 							continue
 						}
 					}
@@ -126,17 +117,17 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 			// Spawn task and non-recoverable errors are sent back to the main task
 			// such as if the connection has been closed.
 			tokio::spawn(
-				send_and_watch_extrinsic(client.clone(), tx.clone(), at, signer.clone(), shared.clone(), config.clone())
+				send_and_watch_extrinsic(rpc.clone(), tx.clone(), at, signer.clone(), config.clone())
 			);
+
 		}
 
 		/// Construct extrinsic at given block and watch it.
 		async fn send_and_watch_extrinsic(
-			client: Arc<WsClient>,
+			rpc: SharedRpcClient,
 			tx: mpsc::UnboundedSender<StakingMinerError>,
 			at: Header,
 			signer: Signer,
-			shared: SharedConfig,
 			config: MonitorConfig,
 		) {
 
@@ -144,20 +135,20 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 			log::trace!(target: LOG_TARGET, "new event at #{:?} ({:?})", at.number, hash);
 
 			// if the runtime version has changed, terminate.
-			if let Err(err) = crate::check_versions::<Runtime>(&*client).await {
+			if let Err(err) = crate::check_versions::<Runtime>(&rpc).await {
 				let _ = tx.send(err.into());
 				return;
 			}
 
 			// we prefer doing this check before fetching anything into a remote-ext.
-			if ensure_signed_phase::<Runtime, Block>(&*client, hash).await.is_err() {
+			if ensure_signed_phase::<Runtime, Block>(&rpc, hash).await.is_err() {
 				log::debug!(target: LOG_TARGET, "phase closed, not interested in this block at all.");
 				return;
 			}
 
 			// grab an externalities without staking, just the election snapshot.
 			let mut ext = match crate::create_election_ext::<Runtime, Block>(
-				shared.uri.clone(),
+				rpc.clone(),
 				Some(hash),
 				vec![],
 			).await {
@@ -184,7 +175,7 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 
 			log::info!(target: LOG_TARGET, "mined solution with {:?}", &raw_solution.score);
 
-			let nonce = match crate::get_account_info::<Runtime>(&*client, &signer.account, Some(hash)).await {
+			let nonce = match crate::get_account_info::<Runtime>(&rpc, &signer.account, Some(hash)).await {
 				Ok(maybe_account) => {
 					let acc = maybe_account.expect(crate::signer::SIGNER_ACCOUNT_WILL_EXIST);
 					acc.nonce
@@ -209,13 +200,7 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 			let extrinsic = ext.execute_with(|| create_uxt(raw_solution, witness, signer.clone(), nonce, tip, era));
 			let bytes = sp_core::Bytes(extrinsic.encode());
 
-			let mut tx_subscription: Subscription<
+			let mut tx_subscription = match rpc.watch_extrinsic(&bytes).await {
-					TransactionStatus<<Block as BlockT>::Hash, <Block as BlockT>::Hash>
-			> = match client.subscribe(
-				"author_submitAndWatchExtrinsic",
-				rpc_params! { bytes },
-				"author_unwatchExtrinsic"
-			).await {
 				Ok(sub) => sub,
 				Err(RpcError::RestartNeeded(e)) => {
 					let _ = tx.send(RpcError::RestartNeeded(e).into());
@@ -267,11 +252,10 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 						let key = StorageKey(
 							frame_support::storage::storage_prefix(b"System", b"Events").to_vec(),
 						);
-						let key2 = key.clone();
 
-						let events = match get_storage::<
+						let events = match rpc.get_storage_and_decode::<
 							Vec<frame_system::EventRecord<Event, <Block as BlockT>::Hash>>,
-						>(&*client, rpc_params! { key, hash })
+						>(&key, Some(hash))
 						.await {
 							Ok(rp) => rp.unwrap_or_default(),
 							Err(RpcHelperError::JsonRpsee(RpcError::RestartNeeded(e))) => {
@@ -281,7 +265,7 @@ macro_rules! monitor_cmd_for { ($runtime:tt) => { paste::paste! {
 							// Decoding or other RPC error => just terminate the task.
 							Err(e) => {
 								log::warn!(target: LOG_TARGET, "get_storage [key: {:?}, hash: {:?}] failed: {:?}; skip block: {}",
-									key2, hash, e, at.number
+									key, hash, e, at.number
 								);
 								return;
 							}

polkadot/utils/staking-miner/src/prelude.rs

@@ -30,11 +30,13 @@ pub type Balance = core_primitives::Balance;
 pub type Index = core_primitives::AccountIndex;
 /// The hash type. We re-export it here, but we can easily get it from block as well.
 pub type Hash = core_primitives::Hash;
+/// The header type. We re-export it here, but we can easily get it from block as well.
+pub type Header = core_primitives::Header;
 
 pub use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
 
 /// Default URI to connect to.
-pub const DEFAULT_URI: &str = "wss://rpc.polkadot.io";
+pub const DEFAULT_URI: &str = "wss://rpc.polkadot.io:443";
 /// The logging target.
 pub const LOG_TARGET: &str = "staking-miner";
 

polkadot/utils/staking-miner/src/rpc.rs

@@ -0,0 +1,166 @@
+// Copyright 2021 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! JSON-RPC related types and helpers.
+
+use super::*;
+use jsonrpsee::{
+	core::{Error as RpcError, RpcResult},
+	proc_macros::rpc,
+};
+use pallet_transaction_payment::RuntimeDispatchInfo;
+use sc_transaction_pool_api::TransactionStatus;
+use sp_core::{storage::StorageKey, Bytes};
+use sp_version::RuntimeVersion;
+use std::{future::Future, time::Duration};
+
+const MAX_CONNECTION_DURATION: Duration = Duration::from_secs(20);
+const MAX_REQUEST_DURATION: Duration = Duration::from_secs(60);
+
+#[derive(frame_support::DebugNoBound, thiserror::Error)]
+pub(crate) enum RpcHelperError {
+	JsonRpsee(#[from] jsonrpsee::core::Error),
+	Codec(#[from] codec::Error),
+}
+
+impl std::fmt::Display for RpcHelperError {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		<RpcHelperError as std::fmt::Debug>::fmt(self, f)
+	}
+}
+
+#[rpc(client)]
+pub trait RpcApi {
+	/// Fetch system name.
+	#[method(name = "system_chain")]
+	async fn system_chain(&self) -> RpcResult<String>;
+
+	/// Fetch a storage key.
+	#[method(name = "state_getStorage")]
+	async fn storage(&self, key: &StorageKey, hash: Option<Hash>) -> RpcResult<Option<Bytes>>;
+
+	/// Fetch the runtime version.
+	#[method(name = "state_getRuntimeVersion")]
+	async fn runtime_version(&self, at: Option<Hash>) -> RpcResult<RuntimeVersion>;
+
+	/// Fetch the payment query info.
+	#[method(name = "payment_queryInfo")]
+	async fn payment_query_info(
+		&self,
+		encoded_xt: &Bytes,
+		at: Option<&Hash>,
+	) -> RpcResult<RuntimeDispatchInfo<Balance>>;
+
+	/// Dry run an extrinsic at a given block. Return SCALE encoded [`sp_runtine::ApplyExtrinsicResult`].
+	#[method(name = "system_dryRun")]
+	async fn dry_run(&self, extrinsic: &Bytes, at: Option<Hash>) -> RpcResult<Bytes>;
+
+	/// Submit an extrinsic to watch.
+	///
+	/// See [`TransactionStatus`](sc_transaction_pool_api::TransactionStatus) for details on
+	/// transaction life cycle.
+	//
+	// TODO: https://github.com/paritytech/jsonrpsee/issues/698.
+	#[subscription(
+		name = "author_submitAndWatchExtrinsic" => "author_extrinsicUpdate",
+		item = TransactionStatus<Hash, Hash>,
+	)]
+	fn watch_extrinsic(&self, bytes: &Bytes) -> RpcResult<()>;
+
+	/// New head subscription.
+	#[subscription(
+		name = "chain_subscribeNewHeads" => "newHead",
+		item = Header
+	)]
+	fn subscribe_new_heads(&self) -> RpcResult<()>;
+
+	/// Finalized head subscription.
+	#[subscription(
+		name = "chain_subscribeFinalizedHeads" => "chain_finalizedHead",
+		item = Header
+	)]
+	fn subscribe_finalized_heads(&self) -> RpcResult<()>;
+}
+
+/// Wraps a shared web-socket JSON-RPC client that can be cloned.
+#[derive(Clone, Debug)]
+pub(crate) struct SharedRpcClient(Arc<WsClient>);
+
+impl Deref for SharedRpcClient {
+	type Target = WsClient;
+
+	fn deref(&self) -> &Self::Target {
+		&self.0
+	}
+}
+
+impl SharedRpcClient {
+	/// Consume and extract the inner client.
+	pub fn into_inner(self) -> Arc<WsClient> {
+		self.0
+	}
+
+	/// Create a new shared JSON-RPC web-socket client.
+	pub(crate) async fn new(uri: &str) -> Result<Self, RpcError> {
+		let client = WsClientBuilder::default()
+			.connection_timeout(MAX_CONNECTION_DURATION)
+			.max_request_body_size(u32::MAX)
+			.request_timeout(MAX_REQUEST_DURATION)
+			.build(uri)
+			.await?;
+		Ok(Self(Arc::new(client)))
+	}
+
+	/// Get a storage item and decode it as `T`.
+	///
+	/// # Return value:
+	///
+	/// The function returns:
+	///
+	/// * `Ok(Some(val))` if successful.
+	/// * `Ok(None)` if the storage item was not found.
+	/// * `Err(e)` if the JSON-RPC call failed.
+	pub(crate) async fn get_storage_and_decode<'a, T: codec::Decode>(
+		&self,
+		key: &StorageKey,
+		hash: Option<Hash>,
+	) -> Result<Option<T>, RpcHelperError> {
+		if let Some(bytes) = self.storage(key, hash).await? {
+			let decoded = <T as codec::Decode>::decode(&mut &*bytes.0)
+				.map_err::<RpcHelperError, _>(Into::into)?;
+			Ok(Some(decoded))
+		} else {
+			Ok(None)
+		}
+	}
+}
+
+/// Takes a future that returns `Bytes` and tries to decode those bytes into the type `Dec`.
+/// Warning: don't use for storage, it will fail for non-existent storage items.
+///
+/// # Return value:
+///
+/// The function returns:
+///
+/// * `Ok(val)` if successful.
+/// * `Err(RpcHelperError::JsonRpsee)` if the JSON-RPC call failed.
+/// * `Err(RpcHelperError::Codec)` if `Bytes` could not be decoded.
+pub(crate) async fn await_request_and_decode<'a, Dec: codec::Decode>(
+	req: impl Future<Output = Result<Bytes, RpcError>>,
+) -> Result<Dec, RpcHelperError> {
+	let bytes = req.await?;
+	Dec::decode(&mut &*bytes.0).map_err::<RpcHelperError, _>(Into::into)
+}

polkadot/utils/staking-miner/src/rpc_helpers.rs

@@ -1,75 +0,0 @@
-// Copyright 2021 Parity Technologies (UK) Ltd.
-// This file is part of Polkadot.
-
-// Polkadot is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// Polkadot is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
-
-//! Helper method for RPC.
-
-use super::*;
-use jsonrpsee::core::client::ClientT;
-pub(crate) use jsonrpsee::types::ParamsSer;
-
-#[derive(frame_support::DebugNoBound, thiserror::Error)]
-pub(crate) enum RpcHelperError {
-	JsonRpsee(#[from] jsonrpsee::core::Error),
-	Codec(#[from] codec::Error),
-}
-
-impl std::fmt::Display for RpcHelperError {
-	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-		<RpcHelperError as std::fmt::Debug>::fmt(self, f)
-	}
-}
-
-/// Make the rpc request, returning `Ret`.
-pub(crate) async fn rpc<'a, Ret: serde::de::DeserializeOwned>(
-	client: &WsClient,
-	method: &'a str,
-	params: Option<ParamsSer<'a>>,
-) -> Result<Ret, RpcHelperError> {
-	client
-		.request::<Ret>(method, params)
-		.await
-		.map_err::<RpcHelperError, _>(Into::into)
-}
-
-/// Make the rpc request, decode the outcome into `Dec`. Don't use for storage, it will fail for
-/// non-existent storage items.
-pub(crate) async fn rpc_decode<'a, Dec: codec::Decode>(
-	client: &WsClient,
-	method: &'a str,
-	params: Option<ParamsSer<'a>>,
-) -> Result<Dec, RpcHelperError> {
-	let bytes = rpc::<sp_core::Bytes>(client, method, params)
-		.await
-		.map_err::<RpcHelperError, _>(Into::into)?;
-	<Dec as codec::Decode>::decode(&mut &*bytes.0).map_err::<RpcHelperError, _>(Into::into)
-}
-
-/// Get the storage item.
-pub(crate) async fn get_storage<'a, T: codec::Decode>(
-	client: &WsClient,
-	params: Option<ParamsSer<'a>>,
-) -> Result<Option<T>, RpcHelperError> {
-	let maybe_bytes = rpc::<Option<sp_core::Bytes>>(client, "state_getStorage", params)
-		.await
-		.map_err::<RpcHelperError, _>(Into::into)?;
-	if let Some(bytes) = maybe_bytes {
-		let decoded = <T as codec::Decode>::decode(&mut &*bytes.0)
-			.map_err::<RpcHelperError, _>(Into::into)?;
-		Ok(Some(decoded))
-	} else {
-		Ok(None)
-	}
-}

polkadot/utils/staking-miner/src/signer.rs

@@ -16,8 +16,9 @@
 
 //! Wrappers around creating a signer account.
 
-use crate::{prelude::*, rpc_helpers, AccountId, Error, Index, Pair, WsClient, LOG_TARGET};
+use crate::{prelude::*, rpc::SharedRpcClient, AccountId, Error, Index, Pair, LOG_TARGET};
-use sp_core::crypto::Pair as _;
+use frame_system::AccountInfo;
+use sp_core::{crypto::Pair as _, storage::StorageKey};
 
 pub(crate) const SIGNER_ACCOUNT_WILL_EXIST: &str =
 	"signer account is checked to exist upon startup; it can only die if it transfers funds out \
@@ -34,17 +35,14 @@ pub(crate) struct Signer {
 	pub(crate) pair: Pair,
 }
 
-pub(crate) async fn get_account_info<T: frame_system::Config + EPM::Config>(
+pub(crate) async fn get_account_info<T: frame_system::Config<Hash = Hash> + EPM::Config>(
-	client: &WsClient,
+	rpc: &SharedRpcClient,
 	who: &T::AccountId,
 	maybe_at: Option<T::Hash>,
-) -> Result<Option<frame_system::AccountInfo<Index, T::AccountData>>, Error<T>> {
+) -> Result<Option<AccountInfo<Index, T::AccountData>>, Error<T>> {
-	rpc_helpers::get_storage::<frame_system::AccountInfo<Index, T::AccountData>>(
+	rpc.get_storage_and_decode::<AccountInfo<Index, T::AccountData>>(
-		client,
+		&StorageKey(<frame_system::Account<T>>::hashed_key_for(&who)),
-		jsonrpsee::rpc_params! {
+		maybe_at,
-			sp_core::storage::StorageKey(<frame_system::Account<T>>::hashed_key_for(&who)),
-			maybe_at
-		},
 	)
 	.await
 	.map_err(Into::into)
@@ -56,10 +54,11 @@ pub(crate) async fn signer_uri_from_string<
 			AccountId = AccountId,
 			Index = Index,
 			AccountData = pallet_balances::AccountData<Balance>,
+			Hash = Hash,
 		> + EPM::Config,
 >(
 	seed: &str,
-	client: &WsClient,
+	client: &SharedRpcClient,
 ) -> Result<Signer, Error<T>> {
 	let seed = seed.trim();